Cardiomyopathy Lecture Notes

Definition

Cardiomyopathy is derived from three parts:
- Cardio: Heart
- Myo: Muscle
- Pathy: Disease
Cardiomyopathy is thus a disease of the heart muscle.

Heart functions as two pumps separated by the lungs:
- Right Heart: Pumps blood from the body to the lungs.
- Left Heart: Pumps blood from the lungs to the body.
Blood circulation process:
- Right heart draws blood from the body and sends it to the lungs for oxygenation.
- Left heart receives oxygenated blood from the lungs and pumps it to the body.
- This cycle is continuous, providing oxygen and nutrients to the body and removing waste.

The heart is composed of muscular walls that expand and contract:
- Relaxation: Chambers expand to draw in blood.
- Contraction: Chambers contract to expel blood.
Heart muscles work simultaneously but independently to ensure efficient blood flow.

Power Failure
- Inadequate muscle contraction results in reduced blood pumping.
- Leads to decreased output of blood from the heart.
Small Pump
- Chambers are too small to hold adequate blood volume, even with full contraction.
- Results in decreased blood flow from the heart.
Blockage
- Obstruction in the heart prevents efficient outflow of blood.
- Also results in decreased blood flow.

Dilated Cardiomyopathy
- Characterized by dilated heart chambers.
- Leads to thin muscle walls and decreased pumping efficiency (power failure).
Restrictive Cardiomyopathy
- Heart muscle walls become thick and rigid.
- Reduces chamber size, limiting blood intake and outflow (small pump phenomenon).
Hypertrophic Cardiomyopathy
- Asymmetrical thickening, typically in the septum.
- Causes blockage of blood flow out of the heart (aorta blockage).

Cardiomyopathy leads to decreased blood outflow due to:
- Pump failure (Dilated Cardiomyopathy).
- Small chamber size (Restrictive Cardiomyopathy).
- Outflow blockage (Hypertrophic Cardiomyopathy).